Tailorable flexible sheet of monolithically fabricated array of separable cells each comprising a wholly organic, integrated circuit adapted to perform a specific function

ABSTRACT

A flexible sheet of organic polymer material, may include a monolithically fabricated array of one or more types of cells juxtaposed among them to form a multi-cell sheet. Each cell may include a self consistent, organic base integrated circuit, replicated in each cell of same type of the array, and shares, in common with other cells of same type, at least a conductor layer of either an electrical supply rail of the integrated circuit or of an input/output of the integrated circuit. A piece of the multi-cell, sheet including any number of self consistent integrated circuit cells, may be severed from the multi-cell sheet by cutting the sheet along intercell boundaries or straight lines, with a reduced affect on the operability of any cell spared by the cutting.

FIELD OF THE INVENTION

The present disclosure relates in general to all-organic integratedelectronic systems.

BACKGROUND OF THE INVENTION

Thin organic film fabrication techniques have led to the realization ofwholly organic integrated circuits and transducers. In particularorganic semiconductors have been successfully used as active layers inorganic thin film transistors (OTFT), in radio frequency identificationdevices (RFIDs), in large-area flexible displays, and in optoelectronicdevices, such as, organic photovoltaic cells. Organic materialsconfigured to change their shape when subjected to an electrical signalor to produce an output signal when subjected to bending, compressive,or tensioning forces have been studied. Among these kinds of “organicsmart materials,” electro-active polymers (EAP) have been extensivelyinvestigated and used to make electromechanical devices with sensingand/or actuating capabilities.

Among EAPs, ionic polymer metal composites and conducting polymers havebeen used for biomimetic sensors, actuators, and artificial muscles.Ionic polymer metal composites (IPMCs) generally include a thinpolymeric membrane having a thickness of about 200 μm, coated, generallyby an electroplating process, with noble metal electrodes, most usuallywith platinum, with a thickness of 5-10 μm. When a voltage is applied,to these electrodes, the IPMC bends, while, when a displacement isapplied, a voltage is measured from the electrodes.

U.S. Pat. No. 6,475,639, entitled “Ionic polymer sensors and actuators”,to Shahinpoor et al. describes methods of making the same forapplications requiring sensing, actuating, and displacement control. Inthis case, the devices are formed by using IPMCs that are polymer metalcomposites. Therefore the devices may be characterized by a metalliccoating of the membrane, forming at least one electrode.

Malone et al. (See, for example, “Freeform Fabrication of IonomericPolymer-Metal Composite Actuators,” and Freeform Fabrication ofElectroactive Polymer Actuators and Electromechanical Devices”) exploredthe possibility of using IPMC and conducting polymers as activematerials to freeform fabricate actuators. (See, for example, “FreeformFabrication of Ionomeric Polymer-Metal Composite Actuators,” andFreeform Fabrication of Electroactive Polymer Actuators andElectromechanical Devices”). Strips of constant pressure (CP) actuatorswere synthesized through electropolymerization from a liquid electrolyteincluding the monomer by growing the polymer film starting from adispersion thereof. In particular, polypyrrole (Sigma-Aldrich), andPEDOT/PSS (Sigma-Aldrich) dispersion in liquid electrolyte wereinvestigated. Moreover, to obtain air-operable actuators, either an ionexchange polymer based membrane as “solid polymer electrolyte” (SPE),which is normally hydrated to allow ion migration therethrough, or aliquid electrolyte confined by some kind of diaphragm was used.

On another account, thin-film and printed batteries with theircustomizable shapes, flexible form factors, and ultra-low weight areenabling new functionality to be added to a broad range of electronicproducts, such as, smart cards, RFIDs, and sensors, both increasingtheir usefulness and the size of their addressable markets.

For these reasons many companies are investing in printable batteriesand photovoltaic research. Varta AG of Hanover, Germany has developed a3V extremely flat lithium-polymer primary cell for use in smart cards.It is embedded in a plastic card with thickness of 0.4 mm and provides acapacity of 25 mAh. Solicore. Inc. of Lakeland, Fla. has also developedan ultra-thin flexible lithium-polymer battery (Flexion), giving anominal voltage of 3V and a capacity of 10 mAh up to 50 mAh and athickness between 0.37 mm and 0.45 mm.

In Italian patent application No. VA2008A000062, by the presentapplicant, a sensor and/or actuator system in which functional circuitryis embedded in an all organic electromechanical transducer device (IP²C)is disclosed. The electromechanical transducer device exploits thebehavior of a flexible sensible ionomeric material sheet as an effectivesensing or actuating member sandwiched between flexible organicelectrodes when undergoing a deformation or being polarized at a certaindrive voltage applied to the electrodes, respectively.

SUMMARY OF THE INVENTION

In studying and developing autonomous functional devices having embeddedpowering means or powering devices and means or devices forcommunicating with the external world, and techniques for to fabricatingall-organic integrated circuits, the applicant found a flexible sheet oforganic polymeric material, having a finite or theoretically unlimitedlength, including a monolithically fabricated array of one or more typesof side-by-side juxtaposed self-consistent cells.

The multi-cell flexible sheet is configured to be cut into pieces of anydesired shape and size, made up by any number of individual cells thatcompose the flexible sheet as manufactured. A piece of the multi-cellflexible sheet may be severable along intercell boundaries or alongstraight cut lines, and it may be bent to conform to uneven surfacesthat may even flutter or change in time with a structure of any kind ofmaterial. Pieces of the flexible sheet may be patched over any support.

Basically, each cell may be self-consistent including an individuallyoperable integrated circuit and transducer element capable of performinga certain function and powering means or device that may include aphotovoltaic element and an energy storing element. The self-consistencyof each individual cell of the multicell (cellular) flexible sheet maymake it possible to cut off even a single cell from the multi-cell sheetfor using it as a fully operative unit (the flexible multi-cell sheet asmanufactured may provide a magazine of severable self consistentfunctional units). More important is the fact that the whole sheet or atailored portion severed from it may be useful for applicationsrequiring a generally large-area “pixel-like” array of independentlyfunctioning cells.

The cells forming the flexible sheet as manufactured may all be areplica of the same integrated system. For example, for applications oflarge-area flexible displays, the cells may comprise optoelectronicdevices based on organic light emitting diodes (OLED), or for large areasurface profile morphing or pressure distribution mapping, the cells maycomprise an organic electro-mechanical actuator or sensor. Themulti-cell sheet may even be made of two or more different types ofcells, replicated all across the flexible sheet according to a certainpre-established pattern, and configured to provide for the replicationof multiple functionalities across the whole area of a tailored piece ofthe multi-cell sheet.

The shape of the cells may be of any geometric shape: polygonal,disc-like, oblong, etc. Preferably, cell shapes and arrangements shouldbe chosen to provide an increased packing degree of the active areas ofthe single cells. The size of the cells may be as small as allowed bythe definition limits of the printing techniques used in the fabricationprocess, and as large as desirable for the contemplated application ofthe multi-cell sheet. Each cell may share, in common with all othercells or at least with all the cells of the same type, at least aconducting layer of the flexible multilayered organic sheet forming anelectrical supply rail or an input/output of the integrated circuit ofthe cells, allowing cells to function in parallel.

Preferably, all the cells share two conducting layers at the front sideand at the rear side of the sheet, respectively, forming common powersupply rails to which every energy storage element of the elementarycells is coupled in parallel. This permits the eventual or optionalpowering of the cells with a unified external source besides obviatingaccidental failure of embedded self powering means or devices of one ormore cells.

The materials used for fabricating the multi-cell sheet are mostlyorganic though inorganic materials, like metals, may also be used. Inany case, materials used should be compatible with the fundamentallyflexible sheet application. NAFION and KAPTON are examples of commercialmaterials for the substrate or backbone layers, and gold and PEDOT forelectrodes and connections. It is desirable that the materials becompatible with flexible, organic base, integrated electronicsfabrication techniques, such as, screen printing, flexography, gravureprinting, inkjet printing, and non conventional lithography, like NanoImprint Lithography (NIL) and Soft Lithography (SL), for example.

Biocompatibility of the component materials may be a requisite for manyapplications of the multi-cell sheet. Lamination may be used forapplying front and rear encapsulating layers of flexible transparentpolymeric material.

The sequence of fabrication steps build up a multilayered organic stackover a rear sealing layer of PET/PEN constituting the substrate. Eachstructured layer is formed in sequence through a number of processingsteps, e.g.: deposition of the layer material, imprinting, and etching,according to common practices in fabricating organic base integratedcircuit devices. Italian patent application No. VA2008A000062, by thepresent applicant includes descriptions of several known fabricationtechniques for fabricating all-organic integrated circuit devices.

The peculiarities of the article of manufacture of the presentdisclosure will be illustrated in more detail in the followingdescription making reference to the drawings annexed to thisspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of a fragment of a monolithically fabricatedflexible sheet of polymeric organic material in accordance with thepresent invention.

FIGS. 2 and 3 show possible severing lines of a piece of the multi-cellsheet.

FIG. 4 shows another plan view of a fragment of a multicellular flexiblesheet of polymeric organic material in accordance with the presentinvention.

FIG. 5 is a schematic diagram of an elementary integrated circuit cellthat is replicated across the flexible sheet of polymeric organicmaterial in accordance with the present invention.

FIG. 6 is a functional block diagram of the integrated circuit of theelementary cell in accordance with the present invention.

FIG. 7 is a cross-sectional view of basic integrated devices that makeup the functional circuit of FIG. 6.

FIG. 8 is a fragmentary cross-sectional view showing the structure of anorganic transistor of the structure of FIG. 7.

FIG. 9 is a fragmentary cross-sectional view of an organic lightemitting diode of the integrated structure of FIG. 7.

FIGS. 10 and 11 are fragmentary cross-sectional views of alternativestructures of the organic photovoltaic device of the integratedstructure of FIG. 7.

FIG. 12 is a fragmentary cross section of a large size capacitor usefulas energy storage element usable in the integrated structure of FIG. 7.

FIG. 13 is a fragmentary cross-sectional view of a thin film batteryusable as energy storage element in an integrated structure as the onedepicted in FIG. 7.

FIG. 14 is a fragmentary partially sectioned integrated structure of anall organic cell including an actuating/positioning/vibrating element asin the prior art.

FIG. 15 is a fragmentary simplified cross-sectional view of anintegrated motion/pressure sensing device as in the prior art andconfigured to be included in an cell of the present embodiments.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an exemplary layout view of a fragment 1 of twelve similarcells that make up a monolithically fabricated flexible sheet ofpolymeric organic material.

From a multi-cell flexible sheet of theoretically unlimited size piecesof the desired size, a certain number of individual cells 2 can besevered off by simply cutting the sheet along severing lines as thoseexemplarily shown in FIGS. 2 and 3. Of course it may also possible tosever a single cell 2 or a fragment composed of a given number ofadjacent cells by cutting along the boundary lines among the cells. Analternative packing layout of cells of two different types and/or sizes2 a and 2 b is illustrated in FIG. 4, showing a fragment of a multi-cellflexible sheet 1 of polymeric organic material of the present disclosureincluding two types of cells of different sizes.

A schematic layout of an elementary integrated circuit cell 2 that isreplicated across the flexible sheet of polymeric organic material isillustrated in FIG. 5. Illustratively, the cell has a perimeter strip 3of a conductive polymer that forms an electrode/pad of the integratedcircuit of the elementary cell. The electrode/pad electrically connectsto similar electrode/pad conductive polymer layers pertaining to similarcells adjacent to the depicted cell. This provides an electricalconnection in parallel of all the cells that include the flexiblemulti-cell sheet as manufactured.

The cell includes an organic photovoltaic (OPV) device 4 and an organiclight emitting diode (OLED) 5. An exemplary functional block diagram ofthe integrated circuit of a sample elementary cell is illustrated inFIG. 6. The OPV 4 provides a source of energy and the energy storagedevice 6 allows the satisfactory powering of the integrated circuit ofthe cell and of an eventual output transducer or communication devicewith the external world. Adequate energy storage capability may beprovided by a relatively large organic capacitor or by a compatiblyintegratable thin film battery.

The integrated circuit entirely formed with OTFT, organic resistors andcapacitors, manages the energy conversion and storage, and may include,in case of the sample cell considered, a pulse driving circuit 7 for theOLED 5, and even a crepuscular switch 8. Pulsed driving of the OLED mayreduce consumption by more than 50%, for example.

A cross-sectional view of the integrated structures of basic integrateddevices that form the functional cell circuit of FIG. 6 is shown in FIG.7. The different shadings illustrate the boundaries of theregions/layers that form the passive and active components of theintegrated circuit and of the powering and light emitting devices of thesample cell. The legend at the foot of the drawing gives the generalcharacteristics of the materials of the different regions/layers. TheOn/Off crepuscolar switch 8 may be implemented by an OTFT controlled bythe voltage generated by the OPV, as illustrated in FIG. 7.

FIG. 8 is a fragmentary cross-sectional view showing the structure ofthe organic transistors (OTFT) of the integrated structure of FIG. 7.The integrated transistor structure comprises the conductive gateelectrode layer 12 being, for example, gold, the high-k dielectric 13layer being, for example, PMMA, the organic semiconductor layer 14being, for example, P3HT (Poly3-HexylThiophene), F8T2, PTAA, orpentacene. The organic semiconductor layer 14 embeds interleavedmulti-fingers of source and drain electrodes 15 and 16 of the sameorganic conductor material with which the gate electrode 12 is made. Thelow-k dielectric material 17, which may be, for example, PolystyrenePolyimide (PI), isolates the integrated OTFT structure.

FIG. 9 is a fragmentary cross-sectional view of the organic lightemitting diode (OLED) of the integrated structure of FIG. 7. Theelectrode layers 18 and 19 may be of the same conductive material asillustrated in the cross-sectional of the integrated structure of FIG.7. The conductive anode layer 21 and the emissive cathode layer 20 maybe chosen from the commercial family of MERCK's Livilux® products, forexample.

FIGS. 10 and 11 are fragmentary cross-sectional views of alternativestructures of the organic photovoltaic device (OPV) of the integratedstructure of FIG. 7. The donor layer 22 may betri[4-(2-thienyl)phenyl]amine ortris[4-(5-phenylthiophen-2-yl)phenyl]amine. The acceptor layer 23 may befullerene, and the hetero-junction layer 24 may be SnPc:C₆₀.

FIG. 12 is a fragmentary cross section of a large size capacitor usefulas energy storage element and usable in the integrated structure of FIG.7. FIG. 13 is a fragmentary cross-sectional view of a thin film batteryusable as an energy storage element in an integrated structure similarto the one depicted in FIG. 7. The encapsulating layer 17 may bePET/PEN, for example.

FIG. 14 is a fragmentary partially sectioned integrated structure of anall organic integrated sensor and/or actuator system in which functionalcircuitry is embedded in an all organic electromechanical transducerdevice (IP²C), as disclosed in Italian patent application no.VA2008A000062, the entire contents of which are herein incorporated byreference. As described in the above noted application, theelectromechanical transducer device exploits the behavior of a flexiblesensible ionomeric material sheet as an effective sensing or actuatingmember sandwiched between flexible organic electrodes when undergoing adeformation or being polarized at a certain drive voltage applied tocounter electrodes of the device.

The integrated system may be replicated in each cell of themonolithically fabricated flexible multi-cell sheet of the presentembodiments, eventually along with an OPV front element for rechargingan embedded micro battery, to provide for different usefulfunctionalities of the tailorable flexible multi-cell sheet. Forexample, the sheet may be useful as a pressure distribution mappingdevice over large surfaces, or as a light operated large area profileactuator.

FIG. 15 is a fragmentary simplified cross-sectional view of anintegrated motion/pressure sensing device as disclosed and illustratedin FIG. 5 of Italian patent application no. VA2008A000062, that is alsoconfigured to be included in an elementary cell of the flexiblemulti-cell sheet of the present embodiments, eventually along with anOPV front element for recharging an embedded micro battery, to providefor yet different useful functionalities of the tailorable flexiblemulti-cell sheet.

That which is claimed:
 1. An article comprising: a flexiblemulti-layered sheet of organic polymer material and comprising an arrayof at least one type of cell in side-by-side relation, each cellcomprising a self-consistent, organic base integrated circuit,replicated in each cell of a same type, and having at least one commonconductor layer being shared with other cells of the same type, aportion of said array comprising a number of said cells being removableso that cells to remain after cutting are operable.
 2. The article ofclaim 1, wherein the at least one common conductor layer comprises oneof an electrical supply rail and an input/output.
 3. The article ofclaim 1, wherein said array is integrally formed as a monolithic unit.4. The article of claim 1, wherein the portion is configured to beremoved by cutting the flexible multi-layered sheet along intercellboundaries.
 5. The article of claim 1, wherein the portion is configuredto be removed by cutting the flexible multi-layered sheet along straightlines.
 6. The article of claim 1, wherein each cell is the same type,and wherein each self-consistent, organic base integrated circuitcomprises an organic base photovoltaic energy conversion device, atleast one organic base thin film transistor coupled to said organic basephotovoltaic energy conversion device, at least one of a thin filmbattery and an organic base tank capacitor configured to store energyconverted by said organic base photovoltaic conversion device, and atleast one of an organic base light emitting diode, an organic baseactuator, and an organic base sensor coupled to said organic basephotovoltaic energy conversion device.
 7. The article of claim 6,wherein each self-consistent, organic base integrated circuit furthercomprises a light sensitive switch coupled to said organic basephotovoltaic energy conversion device.
 8. The article of claim 1,wherein each self-consistent, organic base integrated circuit of eachcell of the same type comprises at least one integrated organic thinfilm transistor (OTFT).
 9. The article of claim 1, wherein said at leastone common conductor layer is shared with all other cells.
 10. Thearticle of claim 1, wherein each self-consistent, organic baseintegrated circuit comprises an energy storage element; wherein said atleast one common conductor layer comprises front and rear commonconducting layers on opposing front and rear sides of saidself-consistent, organic base integrated circuit, said front and rearcommon conducting layer being common power supply rails and coupled inparallel to said energy storage element.
 11. The article of claim 1,wherein each self-consistent, organic base integrated circuit comprisesa conductive polymer perimeter strip configured to electrically coupleadjacent ones of said conductive polymer perimeter strip.
 12. Thearticle of claim 11, wherein said portion of said array is configured tobe removable by at least cutting along said conductive polymer perimeterstrip.
 13. An article comprising: an array comprising at least one typeof cell in side-by-side relation, said array being a flexible organicpolymer material; each cell comprising an organic base integratedcircuit, replicated in each cell of a same type, and having at least onecommon conductor layer being shared with other cells of the same type; aportion of said array being removable therefrom so that a remainingportion is operable.
 14. The article of claim 13, wherein the at leastone common conductor layer comprises one of an electrical supply railand an input/output.
 15. The article of claim 13, wherein said array isintegrally formed as a monolithic unit.
 16. The article of claim 13,wherein the portion is configured to be removed by cutting said arrayalong intercell boundaries.
 17. The article of claim 13, wherein theportion is configured to be removed by cutting said array along straightlines.
 18. The article of claim 13, wherein each cell is the same type,and wherein each organic base integrated circuit comprises an organicbase photovoltaic energy conversion device, at least one organic basethin film transistor coupled to said organic base photovoltaic energyconversion device, at least one of a thin film battery and an organicbase tank capacitor configured to store energy converted by said organicbase photovoltaic conversion device, and at least one of an organic baselight emitting diode, an organic base actuator, and an organic basesensor coupled to said organic base photovoltaic energy conversiondevice.
 19. The article of claim 18, wherein each organic baseintegrated circuit further comprises a light sensitive switch coupled tosaid organic base photovoltaic energy conversion device.
 20. The articleof claim 13, wherein each organic base integrated circuit of each cellof the same type comprises at least one integrated organic thin filmtransistor (OTFT).
 21. The article of claim 13, wherein said at leastone common conductor layer is shared with all other cells.
 22. Thearticle of claim 13, wherein each organic base integrated circuitcomprises an energy storage element; wherein said at least one commonconductor layer comprises front and rear common conducting layers onopposing front and rear sides of said self-consistent, organic baseintegrated circuit, said front and rear common conducting layer beingcommon power supply rails and coupled in parallel to said energy storageelement.
 23. The article of claim 13, wherein each organic baseintegrated circuit comprises a conductive polymer perimeter stripconfigured to electrically couple adjacent ones of said conductivepolymer perimeter strip.
 24. The article of claim 23, wherein saidportion of said array is configured to be removable by at least cuttingalong said conductive polymer perimeter strip.